SQL Server DTS issue with .txt file

Hi,
I have been trying to import/create a new table from a .txt flate file tab delimited, nothing complicated, excepted that by default the string length that the DTS package set for the txt field id varchar (50).
I increased the field length in the mapping window to Nvarchar(max) for fields longer than 50 characters, set the global error to ingnore for each data fields on for the whole file, but the import or create table failed because of the Field Trucation error!
Is this a bug in DTS? How to solve this matter, I spent a great deal of time on it and can't find the solution. I need help.